In a multisite environment, a single installation of ATG products supports more than one Web site, and the sites are configured to share data such as a shopping cart. In such an environment, user profiles are automatically shared across all your Web sites. The profile repository model is identical in a multisite-enabled installation to the model used by an environment that supports only one Web site. For more information, refer to the ATG Personalization Programming Guide. For more information on configuring a multisite environment, see the ATG Multisite Administration Guide.